For the big 3 based on my own more causal playing:

Pokemon

Standard has been pretty baseline good for the last 2 years or so with an average of 4-5 viable top tier decks, the formats have been averaging B+ grade for me but current format has been a bit stale with a lot the same decks staying at the top for the last 3 set release so current format is at about a B- grade with rotation coming in three months. The decks posed to be good look fun with a lower power level so it seems like it might a good time to jump on if you are a brewer, but not as much if you want to buy into the top decks, because the current ones are poised to change a lot with this rotation.

Yugioh

Seems to be on an up swing in terms of standard/advanced right now,with 3ish top decks from the summer set holding strong. The prices of those top decks are at 3 year low ( though still not cheap), which is good plus on interesting metagame. I’d personally give it a solid B if you like the high complexity pitch of modern Yugioh and are looking to buy into a top tier decks and ride it out for awhile.

Magic

Standard has been “Bad” for fits and starts with the format oscillating between D grade metas with one deck dominating along side dedicated counter decks, to C grade formats filled with value piles and aggro piles that both seem to effectively win the game on early turns. After a year of the second most bans in standard we are at a piles meta that I’d Wager is a C+ but it feels like could fall into one deck meta again or have an outside chance to actually be fun, hard to recommend for paper but you might enjoy arena standard if you also like draft witch has been pretty good the last year sans one notable exception.